High yield byproduct recycle process for anhydro sugar alcohols
Patent Information
- Authority / Receiving Office
- US · United States
- Patent Type
- Patents(United States)
- Current Assignee / Owner
- EI DU PONT DE NEMOURS & CO
- Publication Date
- 2004-12-14
- Estimated Expiration
- Not applicable · inactive patent
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Abstract
Description
This invention concerns a process for separating and recycling reaction byproducts in the manufacture of dianhydro sugar alcohols.TECHNICAL BACKGROUND OF THE INVENTIONAnhydro sugar alcohols, in particular derivatives of mannitol, iditol, and sorbitol, are known for their therapeutic uses and uses in food. At least one of these, isosorbide, 1,4:3,6-dianhydrosorbitol, is useful as a monomer used in the manufacture of polymers and copolymers, especially polyester polymers and copolymers.Anhydro sugar alcohols are produced by dehydration of the corresponding sugar alcohols (or monoanhydro sugar alcohols) by the action of various dehydration catalysts, typically strong acid catalysts.Batch processes for the preparation of dianhydro sugar alcohols by acid dehydration are known in the art.In particular, a batch process for the formation of the dianhydro sugar alcohol isosorbide has been described as a two step process involving intramolecular dehydration of sorbitol to 1,4-sorbitan (1,4-mo...